Cylinder Issues
External Cylinder Leakage
External leakage is often an early sign that sealing surfaces or interfaces are no longer stable.
Even small leaks can affect pressure behaviour, system cleanliness and on-site safety.
If left unresolved, it may lead to unstable pitch response and periods of lost wind energy.
Understanding the Problem
What is external leakage?
External leakage occurs when hydraulic fluid escapes from the cylinder to the outside environment.
It typically appears around seals, fittings or interface points where surfaces no longer maintain a stable barrier.
While it can start small, leakage increases contamination risk, reduces hydraulic stability and creates HSE concerns if oil reaches surrounding components.
Typical symptoms
Visible oil residue
Oil traces around the cylinder, rod area or nearby interfaces are often the first clear sign.
Oil on surrounding components
Fluid may spread to hoses, structure or shielding, increasing cleanliness and safety risk.
Low hydraulic oil level / increased top‑ups
Operators may notice more frequent oil additions or a slow drop in reservoir level.
Pressure instability
Loss of fluid can contribute to fluctuating hydraulic pressure, especially during pitch activity.
More frequent pump running
The system may compensate more often to maintain pressure, increasing pump duty cycles.
Irregular pitch response
Pitch movement may feel less consistent under changing wind/load conditions.
Local contamination build‑up
Leaked oil can bind dust and particles, creating residue that accelerates wear and complicates inspection.
Solution
New cylinder
New cylinders provide a clean baseline when the existing cylinder is no longer a responsible long‑term repair candidate. Cylinders supplied through United Wind are updated to current design standards, including the latest sealing concepts. This supports stable operation and reduces the risk of recurring leakage under load.
Solution
Up-tower repair kit
An up‑tower repair kit makes it possible to address leakage directly in the turbine without removing the full cylinder. It reduces handling and workshop dependency, while supporting a safer and more practical execution for technicians. The focus is a durable outcome with minimal operational disruption.
